Modified Zeolite Catalyst Useful for the Conversion of Paraffins, Olefins and Aromatics in a Mixed Feedstock into Isoparaffins and a Process Thereof

ABSTRACT

The invention relates to a modified zeolite catalyst, useful for the conversion of paraffins, olefins and aromatics in a mixed feedstock such as FCC gasoline that contain high content of olefin, aromatic and n-paraffin into isoparaffins. The invention further relates to the use of such a catalyst, for example but not limited to, in a process for the conversion of paraffins, olefins and aromatics in a mixed feedstock into the product having high amount of branched paraffins with decreased aromatics and olefins, a useful gasoline blend, with negligible production of lighter gases.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a modified zeolite catalyst useful forthe conversion of paraffins, olefins and aromatics in a mixed feedstockinto isoparaffins. More particularly, the present invention relates to aporosity and acidity modified zeolite comprising one or two noblemetals. The present invention also relates to a process for theconversion of paraffins, olefins and aromatics in a mixed feedstock intoisoparaffins. The utility of the process is for upgrading the octanenumber of a industrial feedstock such as desulfurized FCC gasolinethrough conversion of most of the olefins and aromatics present in itinto environment friendly branched paraffins, using porosity improved,noble metal containing zeolite based catalyst, so as to meet the qualityrequirement of fuel to use as gasoline blending stock.

2. Description of Related Art

Environmental concern and restriction on fuel quality especially on therestriction on the amount of sulfur, aromatic and olefins in FCCgasoline demands novel catalyst and process for hydrocarbon conversion.The octane loss occurred during traditional sulfur removal process alsodemands hydrocarbon conversion process for octane boosting in aneco-friendly way. The present invention relates to a process forhydroconversion of feedstocks, especially FCC gasoline, to a catalystfor use in hydro conversion process with a feedstock having high amountof paraffins, olefins and aromatics to produce branched paraffin and toa process provides such catalyst.

Reference may be made to the U.S. Pat. No. 4,734,539 to Lawlor et al,wherein a process for the isomerization of paraffins is disclosed. Thedrawback of the process is that the catalyst has one dimensional poresystem that leads to rapid deactivation by coke as well.

References may be made to U.S. Pat. No. 4,962,269 to La pierre et al,wherein a process for isomerization of paraffins using zeolite catalystwas described. The drawback of the process is the formation ofconsiderable amount of aromatics that are undesirable for the productionof green gasoline. On the other hand, the present invention deals withthe conversion of aromatics into iso-paraffins.

Reference may be made to U.S. Pat. No. 5,770,047 to Salazal et al,wherein a process for removal of sulfur and nitrogen from the heavynaphtha was described. The process also describes a GaCr/ZSM-5 catalystfor the isomerization of paraffin. The drawback of the process is theformation of considerable amount of undesirable gases (C1-C4 up to 25%).

Reference may be made to the U.S. Pat. No. 5,057,472, wherein a processfor dealumination of zeolites, especially by adding ammonium nitrate andnitric acid for obtaining effective isomerization catalyst that canisomerizes n-paraffins to isoparaffins. However, the process does notcover the procedure for obtaining the zeolite with improved surfacearea, porosity or acidity and improved Pt dispersion that are essentialfor conversion aromatics, olefins and naphthenes into isoparaffins. Thepatent also does not mention its effectiveness for conversion ofaromatics viz. especially for the conversion of benzene so as to meetthe requirement of gasoline specifications.

Reference may be made to the U.S. Pat. Nos. 5,238,677 and 4,485,005,wherein processes for dealumination of mordenite using an acid such asdicarboxylic acid and steaming have been described. The catalysts aretested for their alpha activity related to its cracking ability and forthe cracking of long chain vacuum gas oil. However, the processes do notdiscuss the improvement in catalytic properties such as porosity andacidity, and its catalytic activity towards the conversion of olefins,naphthenes and aromatics.

Reference may be made to the U.S. Pat. No. 6,964,935, wherein the patentdescribes a process for alkylation of benzene with long chain olefins toproduce alkyl aromatics. The process does not cover the conversion ofshort chain paraffins, olefins, naphthenes and aromatics into gasolinerange isoparaffins. Nitric acid was used for peptization of extrudatesbut not for dealumination purpose.

Reference may be made to the U.S. Pat. Nos. 3,507,931 (MORRIS),4,018,711 (BERTOLACINI), 4,400,576 (SHELL), 3,480,539 (ESSO), wherein aprocess for the isomerization of paraffins was described using a zeolitetreated with steam and acids at severe conditions prior to the contactwith feed. But, the processes limits to the conversion of paraffins intoisoparaffins. Whereas, the present invention deals with the conversionof aromatics, olefins and naphthenes present in the feed intoiso-paraffins. Based on the prior art details and drawbacks thereof, thepresent work is intend to provide a process for the reformulation of theFCC gasoline, where, most of the olefins and aromatics present in thefeed have been converted into branched paraffins using a porositymodified, acidity modified zeolite supported noble metal based catalyst.

SUMMARY OF THE INVENTION

The main object of the invention is to provide a modified zeolitecatalyst, useful for the conversion of paraffins, olefins and aromaticsin a mixed feedstock such as FCC gasoline that contain high content ofolefin, aromatic and n-paraffin into isoparaffins.

Yet another objective is to provide a process for the conversion ofparaffins, olefins and aromatics in a mixed feedstock into the producthaving high amount of branched paraffins with decreased aromatics andolefins, a useful gasoline blend, with negligible production of lightergases.

Yet another object of the present invention is to provide a process forthe conversion of benzene in the hydrocarbon feedstock by saturation andring opening to form iso-paraffins.

Yet another object of the invention is to provide a catalyst forimproving the octane number of the industrial FCC gasoline to at least10-15 units of RON.

Yet another object of the invention is to provide such a hydroconversion catalyst, which provides significant level of isomerizationproduct.

Still another object of the invention is to provide a process forpreparing a catalyst with improved properties such as pore volume,surface area and strong acidity, suitable for the improved production ofbranched paraffins in accordance with the invention.

Some advantages of the present invention are:

-   -   A porosity and acidity improved catalyst that can enhance the        formation of bulky iso-paraffins having high octane number    -   The catalytic process can convert undesired aromatics and        olefins present in the feedstock into environment friendly        isoparaffins.    -   The catalytic process reduces aromatics and olefins in the        feedstock without any octane loss.    -   The process can be used for the improvement of research octane        number (RON) of the feedstocks, at least by 8 units.

Accordingly the present invention provides a modified zeolite catalystwith improved acidity and porosity, useful for the conversion ofparaffins, olefins and aromatics in a mixed feedstock into isoparaffins,said catalyst comprises noble metal incorporated pentasil zeolite basedcatalyst, the composition comprised of:

-   -   Zeolite: in the range of 59-60 wt %;    -   Pseudo extrude: in the range of 39-40 wt %;    -   Pt: in the range of 0.1-1.0 wt %;    -   Pd: in the range of 0-1.0 wt %;        and said catalyst has the following characteristics:

Si/Al in the range of 16-80 BET surface area (m²/g) in the range of200-350 Micropore area (m²/g) in the range of 155-250 External pore area(m²/g) in the range of 90-135 Pore volume (cc/g) in the range of0.30-0.50 Acidity (m · mol/g · catal) in the range of 1.40-1.60 Strong(>120 kJ/mol) in the range of 0.40-0.60 Medium (120-80 kJ/mol) in therange of 0.45-0.50 Weak (<80 kJ/mol) in the range of 0.40-0.60 Ptdispersion (%) in the range of 60-80

In an embodiment of the present invention the modified catalyst has thefollowing composition:

-   -   Zeolite: 59.8 wt %    -   Pseudo extrude: 39.7 wt %    -   Pt: 0.3 wt %    -   Pd: 0.2 wt %

In yet another embodiment, the modified catalyst has the followingcharacteristics:

Si/Al 39 BET surface area (m²/g) 347 Micropore area (m²/g) 248 Externalpore area (m²/g) 99 Pore volume (cc/g) 0.4734 Acidity (m · mol/g ·catal) 1.48 Strong (>120 kJ/mol) 0.58 Medium (120-80 kJ/mol) 0.49 Weak(<80 kJ/mol) 0.41 Pt dispersion (%) 78

In yet another embodiment the modified zeolite catalyst is useful forthe conversion of paraffins, olefins and aromatics in a mixed feedstockinto isoparaffins.

The present invention further provides a process for the preparation ofmodified zeolite catalyst useful for the conversion of paraffins,olefins and aromatics in a mixed feedstock into isoparaffins and thesaid process comprising the steps of:

-   -   treating the zeolite mordenite with steam, at a temperature of        300-700° C., for 2-6 hrs in a shallow bed reactor for        dealumination, followed by washing with 0.01-2N acid solution,        at 100-110° C. for 2-6 hrs and further washing with deionized        water to remove the extra-framework debris of the zeolite and        the nitrate ions;    -   shaping the above said zeolite catalyst obtained in step (a) by        mixing it with an inert alumina binder, preferably pseudo        bemire, with zeolite to binder ratio in the range of 3:1 to        3:2.5 by weight, followed by adding 2-3 vol % glacial acetic        acid and allowing the above said mixture for peptization to        obtain a homogeneous paste, followed by extrusion, drying at        20-30° C., for 10-12 h and calcinations at 500° C. for 2-6 hrs;        and    -   loading the above said extruded catalyst obtained in step(b)        with the noble metal ions by incipient wet impregnation method        (IWI) using Pt tetrammonium chloride and or Pd chloride as a        source of salts, followed by calcination at 500-600° C. for 4-6        hrs to obtain the desired modified catalyst.

In yet another embodiment, the steaming temperature used in step(a) ispreferably in the range of 350-650° C. for a period of 1-4 hr.

In yet another embodiment, the ratio of the volume of the support to theacid solution taken in step (a) is preferably equal to about 50:50.

In yet another embodiment, the acid used in acid solution is selectedfrom the group consisting of hydrochloric acid, sulfuric acid, nitricacid, oxalic acid and mixture of two or more acids.

In yet another embodiment, the noble metals used in step (c) is Pt or Pdor a combination thereof.

In yet another embodiment, the amount of metal used is in the range of0.1 to 1 wt % each.

In yet another embodiment, the surface area and pore volume of thecatalyst material obtained in step (c) is increased by 10-15% and 20-30%respectively after the treatment.

In yet another embodiment, the acidity of the catalyst obtained isincreased to 10-30% after treatment.

The present invention further provides a process for the conversion ofparaffins, olefins and aromatics in a mixed feedstock into isoparaffinswhich comprises feeding FCC gasoline having paraffin, iso-paraffin,olefin, naphthenes and aromatics into the fixed bed down flow reactorcontaining a modified zeolite catalyst comprising noble metals in therange of 0.1 to 1 wt %, under hydrogen flow, at a temperature in therange of 225-375° C., at a pressure in the range of 5-35 bar, at a spacevelocity of 1-6 h⁻¹, followed by cooling of the gaseous product at thereactor tail to obtain the desired product.

In yet another embodiment, the modified catalyst used has a compositionof:

-   -   Zeolite: 59.8 wt %    -   Pseudo extrude: 39.7 wt %    -   Pt: 0.3 wt %    -   Pd: 0.2 wt %

In yet another embodiment, the modified catalyst has the followingcharacteristics:

Si/Al 39 BET surface area (m²/g) 347 Micropore area (m²/g) 248 Externalpore area (m²/g) 99 Pore volume (cc/g) 0.4734 Acidity (m · mol/g ·catal) 1.48 Strong (>120 kJ/mol) 0.58 Medium (120-80 kJ/mol) 0.49 Weak(<80 kJ/mol) 0.41 Pt dispersion (%) 78

In yet another embodiment, the feed stock used contains about 80%olefins and about 60% aromatics.

In yet another embodiment, the feed stock used has an octane number of69 RON.

In yet another embodiment, the octane number of the gasoline obtained isincreased by 20-40% as compared to initial RON number.

In yet another embodiment, the hydro conversion of the feedstockresulted in an increase in octane number in the range of 10 to 15 unitsof RON.

In still another embodiment, the branched paraffins obtained in thefinal product is increased by 30-70% as compared to isoparaffins presentin the feedstock.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with invention, a catalyst system is described whichcomprises a porosity and acidity modified zeolite and a catalyticallyactive phase supported on the support medium and comprising one or twonoble metals.

In an embodiment of the present invention, a catalyst system,particularly a hydrocarbon conversion catalyst was described for use inthe conversion of FCC gasoline and the like so as to convert the olefinsand aromatics into branched paraffins and providing gasoline or gasolineadditives having improved RON/MON values. In accordance with theinvention, the catalyst can also convert the n-paraffins and naphthenesinto branched paraffins and prevent the undesirable aromatic production.

The catalyst system consisting of a silicious molecular sieve supportand an inert binder material, a catalytically active phase consisting ofone or two noble metals, supported or incorporated on the medium, wasdescribed for the reformulation of FCC gasoline. The matrix used wasaluminum, preferably in the form of monohydroxide, and active metalphase is from VIII group of the periodic table, preferably Pt. Thematrix further includes or supports additional metal to change theelectronic properties of the first metal. The second metal includes Ni,Co, Pd most preferably Pd. Of the foregoing metals, the total ratio inthe final catalyst by weight of Pt to Pd is preferably 0.5 to 5, thetotal ratio by weight of metal to support is 0.2 to 1 wt %. Thiscombination of metals provides the catalyst system with improvedcatalytic properties discussed in the examples below.

The support medium is preferably a hydrothermally stable porouscrystalline silicious molecular sieve material, preferably a zeolite ofPentasil type. In accordance with the most preferred embodiment of theinvention, the support material underwent the modification treatment ina hollow reactor at 300° C. to 700° C. in presence of steam followed bywashings with acid such as HCl, HNO₃, H₂SO₄, preferably HNO₃ with acidconcentrations of 0.01 to 1N. The treatment caused considerableimprovement in porosity of the support as discussed in the examplebelow. The support medium preferably has a surface area between 200m²/gm to 350 m²/gm, pore volume of 0.30 to 0.45 cc/g and Si/Al atomicratio of 16 to 80 preferably around 40.

The catalytically active phase which supported on the support mediumpreferably includes at least two catalytically active metals, preferablyPt and the other can be Ni, Co or Pd. Pt and Pd are each present asoxide in the final catalyst in an amount of between 0.01% to about 5% byweight of the catalyst by any means known in the art such asimpregnation, ion-exchange, addition of metal to the molecular sievematerial during its hydrothermal synthesis and the like. Impregnation ispreferably carried out with a salt of the metal in aqueous mediumpreferably salts includes Pt(NH₃)₄ Cl₂, Pd(NO₃)₂.H₂O. Each impregnationis preferably followed by a drying step carried out at a temperaturerange of between 80° C. to 150° C. preferably about 110° C. under flowof air for a period of 3 to 6 hours. Further, the total ratio by weightin the catalyst of Pt to Pd is preferably between 1 to 10. The catalystelements are then calcined in accordance with invention so as to providethe final catalyst. In accordance with invention, calcination is carriedat temperature 600° C. for a period of about 6 hours under flow of air.

The final catalyst exhibits a ratio of Si/M, where M is defined as groupIIIA metal, of between about 15 to 60. The final catalyst preferably hasa Si/M of about 16-80, particle diameter of between 0.5 mm to 3 mm, asurface area of about 200 m²/gm to 350 m²/gm, a pore volume of between0.3 to 0.45 cc/g.

Still further, a process is also disclosed for upgrading olefins rich,aromatic rich FCC gasoline which process comprises the steps ofproviding the FCC gasoline having an initial olefins content, aromaticcontent and initial octane number, and contacting said feedstock with ahydroconversion catalyst system under a hydrogen atmosphere, temperatureand pressure so as to provide a final product having a final olefins andaromatic content less than that of initial FCC gasoline, and having afinal octane number which is 5-15 RON units greater than said initialoctane number of the feedstock, and wherein the final product has anincreased branched paraffin component with effect to said feedstock.

The process as set forth above provides the catalyst of invention, whichyields considerable amount of branched paraffins and potential foroctane boosting of FCC gasoline.

The catalyst is preferably loaded in a fixed bed reactor and contactedwith the feed stock under process condition effective to provide thedesired reaction typically includes the hydrogen pressure 5 to 35 bar,temperature between 225 to 375° C., a space velocity between 1 to 6 h⁻¹.In accordance with the present invention, a process is provided forreducing olefins and aromatics in the FCC gasoline and for the producedbranched paraffin with improved octane number.

The final product obtained after contacting the feed stock with thecatalyst system of the invention is characterized by an upgraded producthaving improved characteristics. The final product exhibits considerableimprovement in the concentration of hydrocarbon types; about 70 to 140%increase in branched paraffins, 30-80% decrease in olefins and 20-60%decrease in aromatics, when compared to those in feed stock. The finalproduct exhibited significant increase in the octane number; 20 to 40%increase in RON.

In an embodiment of the present invention, a catalyst system,particularly a hydrocarbon conversion catalyst was described for use inthe conversion of FCC gasoline and the like so as to convert the olefinsand aromatics into branched paraffins and providing gasoline or gasolineadditives having improved RON/MON values. In accordance with theinvention, the catalyst can also convert the n-paraffins and naphthenesinto branched paraffins and prevent the undesirable aromatic production.

The catalyst according to the invention exhibits improved octane numberby converting olefins and aromatics into branched paraffin as shown inthe examples to follow.

EXAMPLES

The following examples are given by the way of illustration andtherefore should not be construed to limit the scope of the invention.

Example 1

This example illustrates the preparation of two catalysts of theinvention. The chemical composition of the two catalysts is set below inTable 1. The catalysts were prepared as follows. H-mordenite zeoliteswas obtained as support (support-A). Another H-mordenite zeolites wasobtained by treating the “support A” in a shallow bed reactor at 500° C.for 3 hours under steam, followed by washing with 2N HNO₃ and distilledwater. The support obtained after the treatment is called “support B.”Both the supports are used for making two extrudates, where the supportis mixed with pseudo boehmite alumina, added required amount of 3 volume% glacial acetic acid, to obtain a homogeneous paste, which was extrudedand dried. The extrudates obtained are called extrudate A and extrudateB, respectively. The extruded catalyst elements were then impregnatedwith aqueous solution of Pt (NH₃)₄ Cl₂, Pd(NO₃)₂.H₂O. The impregnatedsolid was then dried and calcined so as to provide catalyst described inTable 2.

TABLE 1 Chemical components of the catalyst Catalyst Catalyst A CatalystB Zeolite (wt %) 59.8 59.8 Pseudo extudate (wt %) 39.9 39.7 Pt (wt %)0.3 0.3 Pd (wt %) 0.0 0.2

This example illustrates the importance of steaming and acid washing onthe properties of the zeolites support. Catalyst B is the most preferredcatalyst of the invention and has exhibited improved properties such asenhanced porosity and surface area (about 33% increase in pore volumeand 14% increase in surface area). The support also exhibits improveddispersion of the Pt on the support (Table 2).

TABLE 2 Improvement in properties of the mordenite. Catalyst A CatalystB Si/Al 18 39 BET surface area (m²/g) 292 347 Micropore area (m²/g)158.5 248 External pore area (m²/g) 133.5 99 Pore volume (cc/g) 0.34620.4734 Acidity (m · mol/g · catal) 1.60 1.48 Strong (>120 kJ/mol) 0.420.58 Medium (120-80 kJ/mol) 0.50 0.49 Weak (<80 kJ/mol) 0.62 0.41 Ptdispersion (%) 62 78

Example: 2

This example illustrates the isomerization activity of the catalyst Aand B. The catalysts were used in hydroisomerization of n-hexane atreaction temperature 310° C., pressure 20 bar, H₂/n−C₆=2.1 WHSV=2. Asshown in table 3, catalyst B provided higher n-hexane conversion andisomer yields. As can be seen, the selectivity towards bulky di-branchisomer 22 DHD and 23 DHB significantly high on the catalyst B. Thedi/mono branched isomer ratio indicating the formation of bulky productsincreased from 0.29 to 0.43 (compared to catalyst A). This is an idealsituation for the octane boosting of the product, as branching improvesthe RON of the feed.

TABLE 3 Ability of catalysts in n-hexane conversion Samples Catalyst ACatalyst B n-hexane conversion (wt %) 20.0 36.9 iso-hexane yield (wt %)19.8 36.5 Selectivities (wt % of the total isomer) 2-methyl pentane 48.943.6 3-methyl pentane 28.8 26.6 2,2-dimethyl butane 11.7 14.82,3-dimethyl butane 10.6 15.0 Di/mono ratio 0.29 0.43

Example: 3

Catalyst B of Example 2 was further used in the hydroisomerzation of FCCgasoline (60-FBP). As can be seen in Table 4, the feedstock exhibits thefollowing characteristic, with high level of olefins and aromatics. Thefeedstock also contains the some amount of isomers.

TABLE 4 Feed properties and ASTM distillation Feed Properties Density at15 ° C. 0.7142 Nitrogen 5.5 RVP (Kpa) — Bromine No. 109.3 MAV 2.8 Sulfur(ppm) by XRF 20 ASTM distillation IBP °C. 23.9  5% vol 45.6 10% vol 51.520% vol 55.8 30% vol 60.6 40% vol 67.7 50% vol 75.4 60% vol 86.4 70% vol99.0 80% vol 113.0 90% vol 127.7 95% vol 135.5 FBP °C. 137.9 Totalrecovery % vol 98.6 Residue % vol 1.0

The data given in Table 5 illustrates the hydrocarbon types present inFCC gasoline and their conversion into reformulated product. Thisexample illustrates the hydro-conversion of olefin, aromatic, paraffinfound in the FCC gasoline over the catalyst A and catalyst B. Thehydro-conversion reaction was conducted at similar conditions asmentioned in Example 2. As shown in Table 5, the product obtainedexhibited improved isomer yields. In addition to this, the aromatics andolefin contents are decreased significantly.

A small amount of naphthenes are also formed. This example alsoillustrates that catalyst B is effective for the conversion of olefinand aromatics in FCC gasoline into isomers. About 80% of olefins and 60%of aromatics are converted to increase 140% of branched paraffins in theproduct. The results suggest the mechanism of iso-paraffin formationfrom aromatics and olefins through saturation, ring opening andisomerization. The RON of the feed increased from 69 to 81.

TABLE 5 Catalyst ability in conversion of hydrocarbon types HydrocarbonProduct types Feed Catalyst A Catalyst B n-paraffins 12.5 17.8 14.7Isoparaffins 23.9 37.2 59.0 Olefins 15.9 9.7 2.5 Naphthenes 21.2 16.212.2 Aromatics 26.5 19.1 11.6 Total 100.0 100.0 100.0 RON 69 75.5 81.2

Example: 4

This example illustrates the types of branched hydrocarbons formedduring hydro-conversion of FCC gasoline. As can be seen from Table 6, avariety of branched paraffins are formed after the processing of the FCCgasoline. Catalyst B stands better as the amount of such branchedparaffins formed is 35 wt % against 13.3 wt % over catalyst A. Almostthree (3) times increase in isomer yield was observed on catalyst B andcan be ascribed to the improved catalytic properties of catalyst aftersteaming and acid washings.

TABLE 6 Improvement in branched products Hydrocarbon Catalyst A CatalystB Iso-pentane 1.2 1.9 2-methyl hexane 2.3 4.6 2,3-dimethyl pentane 0.51.1 3-methyl hexane 2.2 4.4 3-ethyl pentane 0.6 1.3 2,5-dimethyl hexane0.4 0.9 2,2,3-trimethyl hexane 0.6 2.2 2-methyl heptane 1.7 4.0 4-methylheptane 0.4 1.1 3-methyl heptane 1.2 4.6 3-ethyl hexane 0.3 3.5 4-methyloctane 0.6 2.8 3-methyl octane 1.1 2.7 Total 13.3 35.1

1.-4. (canceled)
 5. A process for the preparation of modified zeolitecatalyst useful for the conversion of paraffins, olefins and aromaticsin a mixed feedstock into isoparaffins, comprising: a) treating thezeolite mordenite with steam, at a temperature of 300-700° C., for 2-6hours in a shallow bed reactor for dealumination, followed by washingwith 0.01-2N acid solution at 100-110° C. for 2-6 hours and furtherwashing with deionized water to remove the extra-framework debris of thezeolite and the nitrate ions; b) shaping the zeolite catalyst obtainedin step (a) by mixing it with an inert alumina binder, with zeolite tobinder ratio in the range of 3:1 to 3:2.5 by weight, followed by adding2-3 vol % glacial acetic acid and allowing the above said mixture forpeptization to obtain a homogeneous paste, followed by extrusion, dryingat 20-30° C., for 10-12 hours and calcinations at 500° C. for 2-6 hours;and c) loading the extruded catalyst obtained in step (b) with the noblemetal ions by incipient wet impregnation method (IWI) using Pttetrammonium chloride and/or Pd chloride as a source of salts, followedby calcination at 500-600° C. for 4-6 hours to obtain the desiredmodified catalyst.
 6. The process of claim 5, wherein the inert aluminabinder used in step (b) is pseudo boehmite.
 7. The process of claim 5,wherein the steaming temperature used in step (a) is in the range of350-650° C. for a period of 1-4 hours.
 8. The process of claim 5,wherein the ratio of the volume of the support to the acid solutiontaken in step (a) is about 50:50.
 9. The process of claim 5, wherein theacid used in the acid solution is hydrochloric acid, sulfuric acid,nitric acid, oxalic acid and/or a mixture of two or more acids.
 10. Theprocess of claim 5, wherein the noble metal used in step (c) is Pt orPd, or a combination thereof.
 11. The process of claim 5, wherein theamount of metal used is in the range of 0.1 to 1 wt % each.
 12. Theprocess of claim 5, wherein the surface area and pore volume of thecatalyst material obtained in step (c) is increased by 10-15% and20-30%, respectively, after the treatment.
 13. The process of claim 5,wherein the acidity of the catalyst obtained is increased to 10-30%after treatment.
 14. The process of claim 5, wherein the modifiedcatalyst obtained comprises: Zeolite: 59.8 wt % Pseudo extrude: 39.7 wt% Pt: 0.3 wt % Pd: 0.2 wt %.
 15. A process for the conversion ofparaffins, olefins and aromatics in a mixed feedstock into isoparaffins,comprising feeding FCC gasoline having paraffin, iso-paraffin, olefin,naphthenes and aromatics into the fixed bed down flow reactor containinga modified zeolite catalyst comprising noble metals in the range of 0.1to 1 wt %, under hydrogen flow, at a temperature in the range of225-375° C., at a pressure in the range of 5-35 bar, at a space velocityof 1-6 h⁻¹, followed by cooling of the gaseous product at the reactortail to obtain the desired product.
 16. The process of claim 15, whereinthe modified catalyst comprises: Zeolite: 59.8 wt % Pseudo extrude: 39.7wt % Pt: 0.3 wt % Pd: 0.2 wt %.
 17. The process of claim 15, wherein themodified catalyst has the following characteristics: Si/Al 39 BETsurface area (m²/g) 347 Micropore area (m²/g) 248 External pore area(m²/g) 99 Pore volume (cc/g) 0.4734 Acidity (m · mol/g · catal) 1.48Strong (>120 kJ/mol) 0.58 Medium (120-80 kJ/mol) 0.49 Weak (<80 kJ/mol)0.41 Pt dispersion (%)
 78.


18. The process of claim 15, wherein the feed stock used contains about80% olefins and about 60% aromatics.
 19. The process of claim 15,wherein the feed stock used has an octane number of 69 RON.
 20. Theprocess of claim 15, wherein the octane number of the gasoline obtainedis increased by 20-40% as compared to initial RON number.
 21. Theprocess of claim 15, wherein the hydro conversion of the feedstockresults in an increase in octane number in the range of 10 to 15 unitsof RON.
 22. The process of claim 15, wherein the branched paraffinsobtained in the final product is increased by 30-70% as compared toisoparaffins present in the feedstock.